OP0244 AROMATASE INHIBITORS AND FRACTURE PREVENTION – DO NEW GUIDELINES WORK IN REAL WORLD?
Authors: A. Mirza, Z. Win Naing, P. Khonsari, H. Khan, P. Rezai, A. K. Abbas, M. Nisar
Journal: Annals of the Rheumatic Diseases (2022)

Background 2,261,419 women were diagnosed with breast cancer worldwide in 2020. For postmenopausal women with hormone sensitive disease, aromatase inhibitors (AI) are recommended for their mortality benefit. However, AI bone loss (AIBL) is a recognised adverse event with resultant increase in fracture risk. In 2017, a consensus statement of 7 international bone and cancer societies was published proposing an algorithm based on clinical risk factors and different bone mineral density (BMD) threshold for bone active therapeutic intervention. Objectives To determine the real-world impact of the 2017 consensus guidelines on AIBL and whether bone sparing therapy utilising proposed risk stratification model is effective in fracture prevention. Methods Over a 7-year study period, 1001 women were prescribed AI at our university teaching hospital. The new guidelines were adopted in July 2017. We split the participants in two groups: 361 (36%) women had commenced their AI prior to the adoption of guidelines and 640 (64%) were in the post implementation group. First group were offered bone active treatment based on NOS 2009 guidelines whereas the second group followed the 2017 consensus guidelines. Women with osteoporosis were all offered treatment, however the difference in guideline is pertinent to osteopenia and we compared the results of that group. Results 1001 women were included. Mean age was 64 years (range 29-93). 929 (93%) were Caucasian, 57 (6%) were Asian and 15 (1%) were Afro-Caribbean. 723 women (72%) had invasive ductal carcinoma and 863 women (86%) were postmenopausal. At diagnosis, 428 women (43%) had node positive disease and 35 women (4%) had metastases. 91 women (9%) had sustained fractures prior to their cancer diagnosis. 276 women (28%) were offered oral bisphosphonates based on DEXA result, with 58 (6%) offered parenteral therapy. First group: 361 women had a baseline DEXA with a mean left neck of femur (LNOF) BMD of 0.888 g/cm2 (range 0.552-1.222). 143 (40%) women had a normal DEXA, 174 (48%) had osteopenia and 44 (12%) had osteoporosis. Of the women with osteopenia, 44 (25%) women were offered treatment and 33 women had a repeat DEXA after a mean of 4 years. In the treatment group, LNOF mean BMD remained relatively unchanged from 0.814 g/cm2 to 0.812 g/cm2 at the repeat DEXA (p= 0.94). Of the 174 women with osteopenia, 22 (13%) women had a fracture. Second group: 640 women had a baseline DEXA with a mean LNOF BMD of 0.888 g/cm2 (range 0.512-1.390). 216 (33%) women were normal, 322(50%) had osteopenia and 107 (17%) had osteoporosis. Of the women with osteopenia, 127 (39%) women were offered treatment and 56 women had a repeat DEXA after a mean of 3 years. In the treatment group, LNOF mean BMD remained relatively unchanged from 0.822 g/cm2 to 0.829 g/cm2 at the repeat DEXA (p= 0.6169). Of the 322 women with osteopenia, 8 (2.5%) women had a fracture. Conclusion Our study provides real world evidence of the success of 2017 consensus statement in lowering fracture risk. Though there has been data for positive impact on BMD decline with this approach, evidence for fracture prevention has been limited. This study showcases the success of lowering bone active therapy threshold employing alternative risk modelling strategy for women with breast cancer commenced on AI. A significant reduction in fractures pre (13%) and post guidelines change (2.5%) was demonstrated (absolute risk reduction of 10.5%) which has implications for healthcare systems worldwide as we have demonstrated this approach can reduce morbidity. References [1] https://www.wcrf.org/dietandcancer/worldwide-cancer-data/ . Accessed: 26.01.2022. [2]Reid DM, Doughty J, Eastell R, et al. Guidance for the management of breast cancer treatment-induced bone loss: a consensus position statement from a UK Expert Group. Cancer Treat Rev. 2008;34 Suppl 1:S3-S18. [3]Hadji P, Aapro MS, Body JJ, et al. Management of Aromatase Inhibitor-Associated Bone Loss (AIBL) in postmenopausal women with hormone sensitive breast cancer: Joint position statement of the IOF, CABS, ECTS, IEG, ESCEO IMS, and SIOG. J Bone Oncol. 2017;7:1-12. Disclosure of Interests None declared